The objective of this study is to demonstrate the effectiveness and tolerability of the buprenorphine transdermal system (BTDS) (5, 10 and 20) in comparison to placebo transdermal system in subjects with moderate to severe osteoarthritis pain of the hip and knee currently treated with oral opioids. The double-blind treatment intervention duration is 4 weeks during which time supplemental analgesic medication (acetaminophen) will be provided to all subjects in addition to study drug.